Fun with the Radio
Shack EC-4026
(Equivalent of the Casio fx-4500P)
Programming Notes
The syntax for prompting for variables and displaying
results are slightly different from the usual Casio programming language (as I
mentioned, the EC-4026 is a clone of the fx-4500P). Check out the unusual If-Then-Else-End
structure as well.
Prompting Syntax:
{var} : var “prompt
string”
Example:
{X}: X”ENTER X”
Display Syntax:
Calculation
“Display string” ◢ (solid right triangle, [2ndF] [↑])
Example:
X
“F(X)=” ◢
The If-Then-Else-End Structure:
If condition ⇒ do if the condition is true
⇏do if condition is false ◺
(clear right triangle, [2ndF] [√])
Note: I symbolize the [x^y] by ^.
Finding the Monthly Payment of a Mortgage
with Total Interest Paid and Total Cash Outflow
Program MORTGAGE:
L1 Fix 2
L2 {A}: A”LOAN
AMOUNT”
L3 {Y}: Y”YEARS”
L4 {I}: I”RATE”
L5 I = I/1200
L6 N = Y*12
L7 P =
A*(I(1+I)^N)/((1+I)^N-1)
L8 “MONTHLY PMT” ◢
L9 N*P
L10 “OUTFLOW” ◢
L11 N*P-A
L12 “TOTAL INTEREST”
◢
L13 Norm
Example:
A: Loan is $250,000.00
Y: 30 years
I: Interest rate of
4%
Results:
P: Payment:
$1,193.59
Outflow: $429,673.77
Total
Interest: $179,673.77
Midlength, Height, and Area of a Trapezoid
Program TRAPEZIOD:
L1 {A}
L2 {B}
L3 {C}
L3 {C}
L4 {D}
L5 H =
√((-A+B+C+D)*(A-B+C+D)*(A-B+C-D)*(A-B-C+D))/(2*Abs(B-A))
L6 M = (A+B)/2
L7 K = M*H
L8 M
L9 “MIDLENGTH” ◢
L10 H
L11 “HEIGHT” ◢
L12 K
L13 “AREA” ◢
Quadratic Equation
A*x^2 + B*x + C = 0
Program QUAD:
L1 {A}: A”A”
L2 {B}: B”B”
L3 {C}: C”C”
L4 D = B^2-4*A*C
L5 D<0 ⇒ Goto 1 ◺
L6 X = (-B +
√D)/(2A) ◢
L7 Y = (-B -
√D)/(2A) ◢
L8 Goto 0
L9 Lbl 1
L10 X = -B/(2A)
L11 “REAL” ◢
L12 Y = √(Abs
D)/(2A)
L13 “IMAG” ◢
L14 Lbl 0
L15 “DONE” ◢
Example:
3x^2 + 6x – 1 = 0;
A = 3, B = 6, C = -1
Result: 0.154700538, -2.154700538
3x^2 + 6x + 10 = 0;
A = 3, B = 6, C = 10
Result: REAL: -1, IMAG: 1.527525232. -1 ± 1.527525232i
Minimum Loss Matching
Variables:
Input: Y = Z0, Z =
Z1
Output:
R = R1
S = R2
L = Loss Marching
Program MINLOSS:
L1 1: “Z1<Z0” ◢
L2 {Y}: Y”Z0”
L3 {Z}: Z”Z1”
L4 L = √(1 – Z/Y)
L5 R = Y*L: “R1”◢
L6 S = Z/L: “R2” ◢
L7 L = 20 log
(√(Y/Z) + √(Y/Z – 1)): “LOSS” ◢
Example:
Input:
Y: Z0: 15
Z: Z1: 10
Output:
R1: 8.66025 Ω
R2: 17.32051 Ω
Loss: 5.71948
Add Two Polar Numbers
Polar and
Rectangular conversions
|
Variable
|
Rectangular Results
|
Polar Results
|
|
V
|
x
|
r
|
|
W
|
y
|
θ
|
Program ADDPOLAR:
L1 {R}: R”R1”
L2 {S}: S”ANG1”
L3 Rec(R,S)
L4 R = V: S = W
L5 {V}: V”R2”
L6 {W}: W”ANG2”
L7 Rec(V,W)
L8 R = R+V: S = S+W
L9 Pol(R,S)
L10 V: “R SUM”◢
L11 W: “ANG SUM”◢
Example:
4 ∠
20° + 3 ∠ 11 ° (In Degrees Mode)
Result (rounded to
4 digits): 6.9789 ∠ 16.1442°
How to Handle a Tax Bracket (Simple Sample)
Take a sample (and
simplified) tax bracket, where income is X:
0 < X ≤
200: tax rate is 10% of X
200 < X ≤ 600: tax rate is 13% of X
600 < X: tax rate
is 16% of X
Program:
L1 {X}: X”X”
L2 X > 600 ⇒ P = 16: Goto 1 ◺
L3 X > 200 ⇒ P = 13: Goto 1 ◺
L4 P = 10
L5 Lbl
L6 X * P/100
Eddie
All original
content copyright, © 2011-2018. Edward
Shore. Unauthorized use and/or
unauthorized distribution for commercial purposes without express and written
permission from the author is strictly prohibited. This blog entry may be distributed for
noncommercial purposes, provided that full credit is given to the author. Please contact the author if you have
questions.
